Informatica ETL Interview Questions and Answers – Part 1

Informatica Interview Questions & Answers:

A. What are the differences between Connected and Unconnectedlookup?

Connected lookup participates in the mapping(dataflow), just like any other transformation. Unconnected lookup is used when a lookup function is used instead in an expression transformation in the mapping in which case the lookup does not appear in the main flow (dataflow) of the mapping. Connected lookup can return more than one value(output port) whereas an Unconnected lookup gives only one output port. Unconnected lookups are reusable.

Connected transformation is connected to other transformations or directly to target table in the mapping. An unconnected transformation is not connected to other transformations in the mapping. It is called within another transformation, and returns a value to that transformation.

B. When do we use dynamic cache and static cache in connected and unconnected lookup transformations?

Stop command immediately kills the reading process and doesn’t have any timeout period.

Abort command gives a time out period of 60 secs to the Informatica server to finish the dtm process else it kills the dtm process.

G. What is Update Override? What are the differences between SQL Override and Update Override?

Update Override – It is an option available in TARGET instance. By default, Target table is updated based on Primary key values. To update the Target table on non primary key values, we can generate the default Query and override the Query according to the requirement. Suppose for example, if we want to update the record in target table, when a column value=’AAA’ then, we can include this condition in Where clause of default Query.

Coming to SQL override – It is an option available in Source Qualifier and Lookup transformation where we can include joins, filters, Group by and Order by.

Thanks for sharing such a wonderful information! the questions are really useful for the informatica interview. suppose if your looking more about informatica go through Intellipaat informatica interview Q/A’s.

I am loading the data from a source to crm target table. We want to check the manually inserted,updated and deleted records in the target table. Please let me know how this can be achieved..very urgent